Richard Feynman wrote many books during his life time. Some are more assessable then others but all strive to be understood by the layman while still giving even advanced physicists something to think about. Included below is a list of my favorite books by Feynman. He is own of the few authors I have ever read who can make physics really interesting. Note: this is not a comprehensive list.

Six Easy Pieces.
This is a collection of lectures from Fevnman's famous Lectures on Physics given at the California Institute of Technology. In the book, Feynman introduces a number of complex ideas but does not use any equations or incomprehensible jargon.

Six Not-So-Easy Pieces.
This is a second collection of lectures from Feynman's Lectures on Physics. The ideas in this book, including Einstein's Theory of relativity and Space-time, are more difficult then Six Easy Pieces; they contain some formulas. Still, this book can be read by beginning students quite easily and carries a wealth of information that is clearly explained.

Surely You're Joking, Mr. Feynman.
This is a series of anecdotes that basically provide an autobiography of the author.
It's possible to enjoy Surely You're Joking, Mr. Feynman as just a bunch of hilarious stories with the author as know-it-all hero. However, underneath all the merriment there is a commentary on what constitutes authentic knowledge: learning by understanding, not by memorization; a refusal to give up on seemingly insoluble problems; and total disrespect for fancy ideas that have no grounding in the real world. Feynman embodies all of the above.